HIGH FREQUENCY PASSIVE RADIO RANGE FINDER

• US 3,798,647 A
• Filed: 05/25/1972
• Issued: 03/19/1974
• Est. Priority Date: 05/25/1972
• Status: Expired due to Term

• Current Assignee: Albert D. Bailey
• Original Assignee: Albert D. Bailey
• Inventors: Bailey, Albert D.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Blum, T. M.
• Application Number:
  US05/256,961
• Time in Patent Office: 663 Days
• Field of Search: 343/112R,112D,1R,113R
• US Class Current: 342/458
• CPC Class Codes: G01S 11/06 using intensity measurements

Abstract

The application discloses an invention for determining the direction and distance of a remotely located radio source based on the principle that the distance to a station is inversely proportional to the root mean square value or peak value of the received continuous bearing signal as a function of time which has first been passed through a twenty minute averaging or smoothing window.

Claims

1. An improved passive type high frequency radio range finder comprising:

a. A low pass filter having a pass band capable of receiving radio signals in the 3 to 30 mega hertz range that fluctuate about a 20 minute period;

b. A root mean square or peak reading digital voltmeter coupled to said filter, to measure the strength 3 to to mega hertz signal over said period;

c. Means coupled to said voltmeter for determining the root mean square or peak deviation, and;

d. Means including a criteria testing device whereby a most probable range to a radio trasmitter estimate is obtained by comparing invErsely either the root mean square or peak deviation to the range chart.

2. The improved passive type high frequency radio direction finder of claim 1 wherein the input to said filter is coupled to the radio frequency output of conventional radio direction finding equipment.